Start up 3dsmax and make/open your object where u want to have the grille placed, in my case a bumper.

After you have done that, go to the command panel, Select the mouse pointer, and click Shape. Drag a Line

Click now the modify, next to the mouse pointer in the command panel. And fill this in:

Thickness - 1,16 ( you can use more or less. Just how u want it)
Sides - 4
Angle - 0,00

And check Display Render Mesh.

Now the hard part

Select the line, Shift drag it to the right or the left. And once again, move it how u want it. When u release your mouse button you get a nice little pop-up. Choose > Object- Instance and number of copies, just around 200, just that you have enough.